London & North Eastern class P2
For the difficult LNER line between Edinburgh and Aberdeen, Gresley designed the 2-8-2 express locomotive of the class P2. Being the only eight-coupled express locomotive regularly used in Britain, this allowed enough traction on heavy trains on the grades which reached up to 1.34 percent. Only six were built which got names from Scottish lore.
The first one built in 1934, No. 2001 “Cock o' the North”, got Lentz poppet valves and a double Kylchap exhaust. All others received a more conventional Walschaerts valve gear. Also the first later got this type of valve gear. The last four had a longer firebox and there were also changes in production due to problems with smoke lifting. In 1936, they got streamlined fronts.
Due to reliability issues originating from the difficult maintenance under war conditions, Thompson rebuilt all six P2 into A2/2 Pacifics in 1943 and 1944. So no P2 is preserved, but today there are two undertakings which are building a new P2 each. One will be non-streamlined and called 2007 “Prince of Wales”, while the other will be called 2001 “Cock o' the North” and be streamlined, like the original 2001 after it had been rebuilt.
Technical data
General
- Built
- 1934-1936
- Manufacturers
- Doncaster
- Wheel arrangement
- 2-8-2 (Mikado)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Wheelbase
- 11.56 m
- Total wheelbase
- 19.53 m
- Service mass
- 112.3 t
- Adhesion mass
- 81.9 t
- Total mass
- 173.6 t
- Rigid wheelbase
- 5.94 m
- Axle load
- 20.3 t
- Water capacity
- 22,731 l
- Fuel capacity
- 9.1 t (coal)
Boiler
- Grate area
- 4.645 m²
- Firebox surface
- 23.458 m²
- Tube heating surface
- 217.904 m²
- Evaporative heating surface
- 241.362 m²
- Superheater surface
- 69.584 m²
- Total heating surface
- 310.9 m²
Power plant
- Driver diameter
- 1,880 mm
- Boiler pressure
- 15.2 bar
- Expansion type
- simple expansion
- Cylinders
- three, 533 x 660 mm
Power
- Power source
- steam
- Estimated power
- 2,088 kW (2,839 PS)
- Starting effort
- 193.3 kN
Calculated values
- Factor of adhesion
- 1 : 4.16
- Optimal speed
- 66 km/h
- Power-to-weight ratio
- 18.6 kW/t
- Heating Surface Equivalent
- 497.8 m²
- Cylinder volume/HSE
- 1 : 889.31
- Adhesive weight/Total
- 1 : 1.37
- Tractive force/Heating surface
- 1 : 12.99
- Grate area/Heating surface
- 1 : 66.94
- Firebox/Tube surface
- 1 : 9.29
- Total/Superheater
- 1 : 3.47